My best friend and I love to cosplay. Thing is though, our parents are very suspicous and cautious about it. I know most parents have a fear of the unknown, which is understandable, and I appreciate that my parents are protective over me. But they give the impression that they think cosplay is very "iffy." Mum doesn't seem to mind me 'dressing up' as casual/"non-flamboyant" characters; i.e. someone from pokémon, but if I want to try someone more daring (someone from Naruto, or a pokémon gym leader for example) her back gets up a little bit.
She's kind of hinted that she's googled about my "latest obsession", but she's still pretty unsure about what this is all about. I understand how she feels - for me, I picked up the feel of it over time. (An example would be showing someone who had never seen an anime or heard of Vocaloid a video of Miku singing live. ... That kind of clueless, aha.)
My best friend is having a harder time with her parents than I am with mine. So... we need help. How can we explain the concept of cosplay and the otaku fandom that surrounds it to our parents?
Opinions and experiences would be most appreciated! (P.S. I'm sorry if this is gabbled, it's kind of late right now... )

Just keep it basic, that cosplay is dressing up as a fictional character from various sources like anime, films and comics, and people attend events to showcase and generally have fun in their created costumes.
It's a hobby, that many people take part in and it's a way for you to make new friends, have safe fun, and while expensive in some cases, is gratifiying since you're learning new skills.

You know, a lot of people want to educate others about what cosplay is about, and there are a few 'documentaries' (I use quotation marks because not all are officially published and are on youtube) But the info is all there. Opinions from actual cosplayers, footage while AT the con while even interviewing them in their own home environments, so proving that yes, they are normal people too. Just maybe proof-watch it first then try that with your mum?

Look for a Documentary on youtube, there are some really good ones out there, so have a look at a few and pick the best one that you think will help your parents to understand ^^

My Parents were a bit wary to begin with too XD
When I chose my second cosplay as School Uniform version or Rukia Kuchiki, my Mum was like "Hmmm that skirt is a bit... Short" (Bare in mind I was 14 at the time)
It took a while for my parents to come round through the first year but afterwards they just accepted it and now its quite normal for me to talk about cosplay to them and they help give opinions on what will look best on me ^^

Even now, when I am 18, they still say "That skirt is a bit short" but oh well XD

My mum hates cosplay, anime and anything of the sort so I have to cosplay in secret, and trust me it is not the way to go xD I have no idea how to convince her its not some fetish/ cult or whatever she thinks it is :'

A way that I eased my parents into my own cosplaying was by printing out pictures of who I wanted to work on, and showing it to them. They knew I was into anime and other cartoons already, though, so that might have helped with the transitioning.

So long as I just sort of ran it past them what I was going to be up to, and they saw the character design, they'd be okay with it. It's just getting them to understand how harmless it is, and that it's purely a fun hobby :3

I started when I was a bout 16, my mum helped me loads when it came to wearing a Kimono and even helped me make the obi!

When I wanted to do Tohru from Fruits Basket though things changed, she did not like! Things got worse and when I moved out at 18, they sat me down and said I should give up this "childish hobby"

I didnt (clearly), and they're still not happy about it, it's harder when you're younger since you depend on them so much, I'm 24 now, I still love cosplaying, I have a massively supportive and amazing husband who funnily enough looooves my cosplay!

It's a shame they can't get over their own prejudices (massive catholics) but I know that if I have kids one day, I'll respect them for their choices - even if they want to cosplay digimon *shudders*

To be honest my parents were a little strict at first my mum was really worried. So i showed her a couple of videos from the expos to show her its ok and that you arent the only one who does it ^^. She soon enough was happy for me to cosplay and now encourages me to carry on as I enjoy it so much

So just show them videos of expos make them become more familiar to it

My first costume was a miniskirted catgirl affair (complete with fur armwarmers, legwarmers and ear bands) where me and my ex both went in twinned costumes.

Not sure what my Mum thought about it at the time - I was 17 and not particularly under the thumb at any point, so I probably started putting the costumes together and just went 'Oh yeah, me and X are dressing up as catgirls. With ears.' But then my Mum is a very accepting person.

A few years on and I'm living with my boyfriend, who despite being a nerd is not a geek, and doesn't read comics or manga or watch any anime. My Lady Sif doesn't bother him, though he did make a comment about my legs getting cold! I think he still thinks I'm weird, but in a good way!

Have patience. It can be difficult explaining that what you're doing isn't fetishy or anything, but give it time. If worst comes to worst - show them Cosplay Island? Full of lovely people

Haha, bless your cotton sock. I feel for you! My mum thinks i'm insane! I'm having a hard time convincing her that cosplay is a marvellous thing -____-

However i'm 20 now and there's nothing she can do to stop me And I think she's kind of happy that i'm not spending all my free time just watching anime and playing ps3 and i'm actually doing something sort of productive.

Cosplay is a good excuse to learn how to sew, which is always a handy skill! So maybe drop that in a conversation with her sometime haha

Maybe take her to an event? She can see what it's all like with her own eyes.

"Look, it's a bit of an odd hobby but I'm glad you're doing something productive rather than going out, getting hammered then having to have your stomach pumped, or getting hooked on drugs or something. It'll only become an issue if you became a prostitute to fund the bloody expenses of it!"